Mibew Messenger use
Symfony for routing.
If you proxying https-requests to http-backend, just set several environmental variables related to protocol (namely,
HTTPS should be set to
on and
HTTP_SCHEME to
https), and Symfony will do the magic.
Alternatively, one could alter the
config/routing.yml this way. But I wouldn't recommend that way: one will have to manually update routes during each system update.